While the invention is subject to a wide range of applications, it is particularly suited for a moving vehicle requiring bumpers. In particular, a vehicle such as a mobile robot which incorporates the bumper of the present invention is able to navigate by sensing both the force and the position of a collision with an object.
Bumpers for obtaining tactile sensory information from the perimeters of associated autonomous mobile robots or platforms, for the purpose of impact detection and collision avoidance, are well known in the prior art. The prior art tactile bumpers for accomplishing the foregoing generally consist of independent and discrete elements arranged in a discontinuous fashion around the mobile robot or platform being protected.
One such prior art bumper, disclosed in U.S. Pat. No. 3,599,744, is connected by a hinge to a vehicle. The bumper is formed of an elastically deformable material. When the bumper contacts an obstruction, it pivots about hinge pins and opens a switch causing the vehicle to decelerate or brake. This bumper is not able to distinguish the location or force of contact with the bumper.
It is also known in the prior art to provide a bumper which is able to determine the position of an obstacle relative to the vehicle. For example, U.S. Pat. No. 4,546,840 discloses a metal bumper having an obstacle contact sensor comprising a conductive rubber member sandwiched between a protective thin metal film and an electrode plate. The electrode plate has a plurality of electrode surfaces in contact with the metal bumper. Compression of the rubber member electrically grounds the corresponding electrode surface through the conductive rubber having a reduced electrical resistance whereby the electrical potential of the electrode surface is lowered. A resulting electrical signal enables the presence of an obstacle to be sensed. In addition, the location of where the obstacle contacts the vehicle body can be sensed with the switch mechanism on the electrode surface. The '840 patent does not disclose a means to determine the force of contact between the bumper and the obstacle.
Another prior art bumper for a mobile robot is disclosed in U.S. Pat. No. 4,596,412. The prior art bumper disclosed therein is configured to obtain sensory information for impact detection and collision avoidance from the entire perimeter of an associated autonomous mobile robot or platform.
The prior art, as indicated hereinabove, includes some advancements in bumpers for impact detection and collision avoidance. However, insofar as can be determined, no prior art tactile bumper incorporates all of the features and advantages of the present invention.
It is a problem underlying the present invention to determine both the position and force of impact on a bumper attached to a vehicle.
It is an advantage of the present invention to provide a bumper for impact detection which obviates one or more of the limitations and disadvantages of the described prior arrangements.
It is a further object of the present invention to provide a bumper for impact detection which can sense the location of contact with an obstacle.
It is a still further object of the present invention to provide a bumper for impact detection which can sense the force of impact with an obstacle.
It is yet another advantage of the present invention to provide a bumper for impact detection which can sense a very low force of impact.
It is a still further advantage of the present invention to provide a bumper for impact detection which is relatively inexpensive to manufacture.
Accordingly, there has been provided a bumper for impact detection with an object. An electrically conductive member has a compressible, electrically conductive material mounted thereto. An insulator formed of mesh material is sandwiched between the electrically conductive member and the electrically conductive material for electrically insulating the conductive member from the conductive material when the material is in a non-compressed state and for providing electrical conduction between the conductive member and the conductive material when the conductive material is in a compressed state.